Lateral seismic brace

ABSTRACT

A sway brace fitting clamp is used for lateral bracing of sprinkler or other types of pipe (designated the service pipe) to a structure, to prevent movement of the service pipe perpendicular to the axis of a sway brace relative to the structure to which it is attached. The sway brace fitting clamp includes a body which fits around the service pipe, and a pair of hooks that are coupled to the body, for hooking the sway brace. The nuts may be tightened to pull the sway brace into contact with the service pipe, or otherwise firmly clamping the sway brace and the service pipe together.

This application is a continuation-in-part of U.S. application Ser. No.12/356,622, filed Jan. 21, 2009, which claims priority under 35 USC 119from U.S. Provisional Application No. 61/022,406, filed Jan. 21, 2008.Both of the above applications are incorporated herein by reference intheir entireties.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention is in the field of seismic bracing and sway braces.

2. Description of the Related Art

Seismic sway bracing is often required for plumbing systems, firesprinklers, electrical systems, heating conduits, ventilation conduits,air conditioning conduits, and other structural and non-structuralcomponents of a building as well as some equipment installed inbuildings. One way of sway bracing is to couple a system to be braced toa pipe or other rigid structural member that is in turn coupled tobuilding structure, such as a wall, ceiling, or a building structuralmember.

SUMMARY OF THE INVENTION

An aspect of the invention involves a lateral sway brace fitting inwhich the sway brace pipe is tangential to the outside diameter (OD) ofthe service pipe, and perpendicular to the longitudinal axis of theservice pipe. It is made up of three different components: a wireformbody, two stamped attachment hooks, and two swivel nuts.

The main body of the sway brace fitting is a U-bolt that wraps around aservice pipe. The “U” shape allows the sway brace fitting to be placedon the service pipe through the open end of the “U”. It is a wireformthat is of sufficient diameter to remain stiff when subject to testloads. For a sample embodiment, the wireform may be wire diameter usedto upset a ⅝″-11 thread. The inside diameter of the wire is sized to fitsnugly to the service pipe. Standard sizing for schedule 40 and schedule80 steel pipe was referenced for the configuration, but it will beappreciated that other pipe sizes may be used. Normal clearance wasapplied to the standard diameter to determine the inside diameter (ID).A novel feature of one embodiment of the U-bolt is the shortened legs ofthe U. A typical U-bolt has extra length on the legs to aid withassembly. However for one embodiment the intended use of the tips of thelegs is to engage the sway brace pipe. The length of the legs isdetermined by the plane defined by the tangency of the service pipe andthe sway brace pipe. At the tips of the U-bolt legs are conicalprotrusions used to engage the sway brace pipe. This engagement iscaused by the components described further below. The conical tips aregenerated prior to forming of the wire into a U-shape. These tips can becold-worked or thermally treated to gain additional hardness to improvethe ability of the conical shape to penetrate into the sway brace pipe.

According to another specific embodiment, the ID of the U-bolt isdesigned to fit, with minimal clearance, on the sprinkler system pipe.Standard sizing for ASTM A53 and ASTM A795 steel pipe was referenced forthe configuration, although it will be appreciated that other pipe sizescould be used. Another feature of the U-bolt is a pair of offsets,applied to widen the legs of the “U”. This geometry preventsinterference between the u-hooks and the sprinkler system pipe duringthe process of installation.

According to one embodiment, at each end of the U-bolt is a formed hookcomponent. It provides a frame with which to capture the sway brace pipeand to support the loads of embedding the tips of the U-bolt in the swaybrace pipe. The “U” shape provides symmetric loading between one tip ofthe U-bolt and the portion of the sway brace pipe which it engages. Thegeneral shape of the hook component is a “U” with squared corners and aflat bottom. In the sides of the “U” are open cutouts into which thesway brace pipe can be inserted and in which the sway brace pipe isclamped. The open side allows for the pipe to be inserted perpendicularto the axis of the pipe at any longitudinal position, without thenecessity of feeding the pipe though the clamp longitudinally. The openslot has a “V” shaped root sufficiently opposite the closed end of the“U”. The “V” shape root is sized so that several sizes of sway bracepipes can be clamped into it. In particular, it may be sized for 1″ and1.25″ (25.4 mm and 38.1 mm) steel pipe. The closed end of the “U”, aspreviously mentioned, is flat. This is to accommodate a swivel nut. Theswivel nut engages the threaded portion of the main U-bolt of the swaybrace fitting and bears against the flattened portion of the “U” shapedhook component. This interaction allows the tip of the U-bolt to bedriven into the sway brace pipe, and is resisted by the V-shaped root inthe open slot of the hook component.

One method of creating the “U” shaped component with a flat bottom isstamping. However, other possible manufacturing processes are casting,forging, or machining. A typical thickness is 0.25″ (6.4 mm). Typically,the width would be sufficiently larger than the sway brace pipe in orderto capture the sway brace pipe and carry the required load around it.This may be approximately 3″ (76 mm).

The final component is a swivel nut. Two possibilities for the swivelnut for use with this embodiment are described herein. The first is theswivel-hex-shear-rivet-nut. Simply, it is a hollow rivet with a centralflange and internal thread. One end of the rivet has a hex shapedoutside. The opposite end is thin and tubular. During installation, thethin tube is swaged to loosely capture the stamped “U” component. Thehex allows the rivet-nut to be rotated by a wrench.

The second is threaded internally, has a flange at one end, acylindrical shaft portion, and a hex at the end opposite the flange. Thenut is inserted into the “U” shaped stamped component. The flange bearsagainst the inside of the closed end of the “U”. The cylindrical shaftportion locates and guides the nut within a hole in the “U” shapedstamped component. The hex provides a means for a wrench to engage thenut.

The stamped hook ends are stored loose on the U-bolt and rotated to beflat with the plane of the U-bolt for ease of shipping. Duringinstallation, they are rotated perpendicular to the plane of the U-boltand slid into position on the swivel nut. The open sides of the twohooks can be oriented in the same direction, or in opposite directions.

Within the assembly, a square plastic washer can be used as a detent toprevent rotation of the stamped hook end to further aide installation.Alternatively, the detent mechanism can be made of another material suchas spring steel.

According to another embodiment, at each end of the U-bolt is a formedhook component to provide a frame that captures the sway brace pipe andtransmits the clamping forces from the U-bolt to the sway brace pipe.The general shape of the hook component is a “U” that wrapsapproximately 180° of the U-bolt thread, and projects tangentially.

The sides of the “U” are open cutouts with a skewed “V” profile. The “V”profile is generally perpendicular to the “U” shape of the formedcomponent, and open in the direction of the closed end of the U-bolt.The “V” shape profile is sized so that several sizes of sway brace pipescan be clamped into it. In particular, it is sized for 1 inch (25.4 mm)and 1.25 inch (31.8 mm) diameter steel pipe. The angle of the “V” may beapproximately 60° from parallel to the U-bolt. This angle serves to pullthe sway brace pipe to a position of close proximity to the U-bolt. The“V” profile has tooth-like protrusions that point generally inward tothe sway brace pipe. Under clamping forces, the teeth improve the loadtransfer capability from the sway bray pipe to the sway brace fitting.

The clamping force generated by a torque-limiting nut on the U-bolt isapplied to the hooked end along the axis of the portion of the hookedend that wraps the threaded portion of the U-bolt. The clamping forceapplied to the hooked end by the nut is resisted by the brace pipe atthe open “V” profile. These two, non-collinear, forces on the hooked endimpart a moment. The moment is resisted by the side of the hooked endopposite the position of the nut by contact with the threaded portion ofthe U-bolt. To complete the resisting moment, another contact point wasadded in the form of a rivet. The rivet spans the “U” shaped form of thehooked end, and is positioned tangential to the threaded portion of theU-bolt and is located in close proximity to the nut.

Clamping pressure is accomplished through the use of two nuts. One nutis threaded onto each end of the U-bolt. The nuts used may be torquelimiting. The torque-limiting mechanism of the nut is a reducedcross-section between a threaded portion of the nut and a drivingportion. Upon application of a predetermined level of torque, thereduced cross-section will fracture, preventing the application of moretorque to the nut.

According to an aspect of the invention, a sway brace fitting clampincludes a single U-bolt that surrounds a pipe and that has sharpenedends or tips that engage a bracing pipe clamped to the surrounded pipe.

According to another aspect of the invention, a sway brace fitting clampincludes a hooked connection between a U-bolt and a brace pipe thatallows for the brace pipe to be drawn onto the sharpened ends or tips ofthe U-bolt.

According to yet another aspect of the invention, a sway brace fittingclamp includes a hooked end that is notched such that it can accommodatemultiple sizes of brace pipes, such as both 1 inch (25.4 mm) and 1.25inch (31.8 mm) diameter pipes. This is accomplished with a notch with aV-shaped root. The hook is open, allowing for quick attachment to thebrace pipe, by sliding onto the brace pipe in a direction perpendicularto the brace pipe at any longitudinal position of the brace pipe,without the installer being required to feed the pipe through the clamp.

According to still another aspect of the invention, a sway brace fittingclamp includes a swiveling-hex-shear-rivet-nut that provides theconnection between the hooked ends that engage a brace pipe, and aU-bolt that captures a service pipe (or other object). The swivel allowsfor relative motion, and therefore adjustment of the threadedconnection. The shear features allows for a maximum torque limit on thefastener. The rivet feature allows for a quick means to secure thecomponent to the hooked end.

According to a further aspect of the invention, a sway brace fittingclamp includes a single U-bolt that surrounds, and provides means forengaging, a sprinkler system pipe or other round object.

According to a still further aspect of the invention, a sway bracefitting clamp includes a hooked connection between a U-bolt and a swaybrace pipe that provides a means for the brace pipe to be drawn onto asprinkler system pipe (or other object to be braced).

According to another aspect of the invention, A hooked end that isnotched such that it can accommodate both 1 inch (25.4 mm) and 1.25 inch(31.8 mm) brace pipes. This is accomplished by the notch having agenerally v-shaped root. The hook is open, allowing for quick attachmentto the brace pipe, by sliding the brace fitting onto brace pipe in adirection perpendicular to the axis of the brace pipe. This action canbe performed at any longitudinal position of the brace pipe, without theinstaller being required to feed the pipe through the clamp.

According to still another aspect of the invention, The v-shaped notchof said hooked ends contains sharp protrusions, directed generallyinward to the “V”. These protrusions or “teeth” increase the strength ofthe connection between the hook of the clamp and the brace pipe.

According to a further aspect of the invention, a clamp includesoffsets, integral to a U-bolt, which produce clearance between thehooked end and sprinkler system pipe for unobstructed installation.

According to a still further aspect of the invention, a clamp includestorque limiting nuts that, in combination with a U-bolt, produce theclosure force on the hooked ends, and clamping between all components.

According to another aspect of the invention, a clamping device is alateral sway brace fitting in which the sway brace pipe is tangential tothe OD of the sprinkler system pipe and perpendicular to thelongitudinal axis of the service pipe. It is made up of three differentcomponents; a wireform body, two attachment hooks, and twotorque-limiting nuts.

According to yet another aspect of the invention, a sway brace fittingclamp for coupling a sway brace pipe to an object includes: a U-shapebolt having a central curved body and a pair of threaded ends emanatingfrom the central body; a pair of hooks coupled to respective of theends; and nuts threaded onto the threaded ends, wherein the nuts can berotated to bear against the hooks to move the hooks toward the curvedbody.

According to still another aspect of the invention, a method of seismicbracing includes: placing a sway brace pipe substantially perpendicularto a service pipe; after the placing, engaging the sway brace pipe andthe service pipe with a sway brace fitting clamp, wherein the engagingdoes not require movement of either of the pipes; and tightening thesway brace fitting clamp to couple together the sway brace pipe and theservice pipe.

According to a further aspect of the invention, a sway brace fittingclamp for coupling a sway brace to an object, includes: a curved bodythat wraps around the object; a pair of hooks coupled to respective endsof the body, wherein the hooks engage the sway brace pipe on oppositesides of the object, and wherein the hooks have openings for receivingthe sway brace; and a threaded engagement that may be tightened to clampthe sway brace and the object together.

According to a still further aspect of the invention, a method ofseismic bracing includes the steps of: placing a sway bracesubstantially perpendicular to a service pipe; after the placing,engaging the sway brace and the service pipe with a sway brace fittingclamp, wherein the engaging does not require movement of either of thepipes; and tightening the sway brace fitting clamp to couple togetherthe sway brace and the service pipe.

Unless it is indicated otherwise, it is to be understood that the aboveaspects of the invention and the features of the embodiment(s) of theinvention described below, may be combinable in a single device, invarious combinations.

To the accomplishment of the foregoing and related ends, the inventioncomprises the features hereinafter fully described and particularlypointed out in the claims. The following description and the annexeddrawings set forth in detail certain illustrative embodiments of theinvention. These embodiments are indicative, however, of but a few ofthe various ways in which the principles of the invention may beemployed. Other objects, advantages and novel features of the inventionwill become apparent from the following detailed description of theinvention when considered in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Annexed are drawings depicting one or more embodiments of the invention.The drawings are not necessarily to scale.

FIG. 1 is an oblique view of a sway brace fitting clamp joining togethera sway brace pipe and a service pipe, in accordance with an embodimentof the present invention.

FIG. 2 is a side view of the sway brace fitting clamp of FIG. 1.

FIG. 3 is an end view of one of the hooks of the sway brace fittingclamp of FIG. 1, showing one possible configuration.

FIG. 4 is an end view of one of the hooks of the sway brace fittingclamp of FIG. 1, showing another possible configuration.

FIG. 5 is a side view of a shear nut usable as part of the sway bracefitting clamp of FIG. 1.

FIG. 6A is a side view of a shear-rivet nut usable as part of the swaybrace fitting clamp of FIG. 1.

FIG. 6B is a side view of the nut of FIG. 6A, showing the nut in itsriveted condition.

FIG. 7 is an oblique view of a sway brace fitting clamp joining togethera sway brace pipe and a service pipe, in accordance with an alternateembodiment of the present invention.

FIG. 8 is an oblique view of a sway brace fitting clamp joining togethera sway brace pipe and a service pipe, in accordance with anotherembodiment of the present invention.

FIG. 9 is an exploded view of the clamp of FIG. 8.

FIG. 10 is a detailed view of part of the sway brace fitting clamp ofFIG. 8, showing the coupling of a hooked end of the clamp with a swaybrace pipe.

FIG. 11 is a side view of a shear nut of the clamp of FIG. 8.

FIG. 12 is a sectional view of the shear nut of FIG. 11.

FIG. 13 is an oblique view of a sway brace clamp in accordance with yetanother embodiment of the present invention.

FIG. 14 is an end view of the clamp of FIG. 13.

FIG. 15 is an end view of a sway brace clamp in accordance with yetstill embodiment of the present invention.

FIG. 16 is an oblique view of the clamp of FIG. 15.

FIG. 17 is an oblique view of a sway brace clamp in accordance with afurther embodiment of the present invention.

FIG. 18 is an end view of the clamp of FIG. 17.

FIG. 19 is an oblique view of a sway brace clamp in accordance with afurther embodiment of the present invention.

DETAILED DESCRIPTION

A sway brace fitting clamp is used for lateral bracing of sprinkler orother types of pipe (designated the service pipe) to a structure, toprevent movement of the service pipe perpendicular to the axis of thepipe relative to the structure to which it is attached. The sway bracefitting clamp includes a U-bolt which fits around the service pipe, anda pair of hooks that are coupled to straight ends of the U-bolt, forhooking the sway brace pipe. A pair of nuts engages threaded portions ofthe U-bolt ends. The nuts may be tightened to pull the sway brace pipeinto contact with the service pipe, firmly clamping the sway brace pipeand the service pipe together.

A sway brace fitting clamp is used for lateral bracing of sprinkler orother types of pipe (designated the service pipe) to a structure, toprevent movement of the service pipe perpendicular to the axis of a swaybrace relative to the structure to which it is attached. The sway bracefitting clamp includes a body which fits around the service pipe, and apair of hooks that are coupled to the body, for hooking the sway brace.The nuts may be tightened to pull the sway brace into contact with theservice pipe, or otherwise firmly clamping the sway brace and theservice pipe together.

Following are relevant definitions:

1) STRUCTURE ATTACHMENT FITTING—A device used to attach a sway bracedirectly to the building structure;

2) SWAY BRACE—A rigid structural member, typically a piece of steelpipe, bar, threaded rod, strut, or angle, whether of a size generallyreferred to as “sway braces” or “branch line restraints,” intended toattach the sprinkler system pipe (or other object to be braced) to abuilding structure using a sway brace fitting attached to the sway braceand sprinkler system pipe (or other object to be braced); and astructure attachment fitting attached to the sway brace and buildingstructure;

3) SWAY BRACE ASSEMBLY—A structural system consisting of a sway braceconnected to a sway brace fitting attached to the sprinkler system pipe(or other object to be braced) on one end and connected to a structureattachment fitting attached to the building on the other. Theseassemblies are intended to connect sprinkler system piping or otherpiping systems (or other object to be braced) to a building structure toprovide resistance to relative horizontal movement between the buildingand the sprinkler system piping or other piping systems (or other objectto be braced) during an earthquake or other shock waves impacting abuilding; and

4) SWAY BRACE FITTING—A device used to attach a sway brace to thesprinkler system piping (or other object to be braced).

Referring initially to FIGS. 1-4, a clamp or brace fitting 10 is shownfor coupling a sway brace pipe 12 to a service pipe or other object tobe braced 14. The clamp 10 includes a U-shape wire form, a U-shape bolt18 that wraps around the service pipe 14 (or other pipe or circularobject). The U-shape bolt 18 has a curved central portion 20, and a pairof legs 22 and 24 extending from opposite sides of the central portion20. The central portion 20 receives the pipe 14, and is against the pipe14 when the clamp 10 is installed, with the legs 22 and 24 extendingalong opposite diametrically-opposed sides of the pipe 14. The legs 22and 24 may be straight extensions from the central bolt portion 20.Alternatively, the legs may have one or more bends that change theoffset between different parts of the legs 22 and 24. The legs 22 and 24have threaded portions 26 and 28. The threaded portions 26 and 28 mayterminate at a plane of tangency 30 between the service pipe 14 and thesway brace pipe 12, when the clamp 10 is installed. The threadedportions 26 and 28 may have a left-handed thread for more intuitiveassembly. The legs 22 and 24 may have tips, such as the tip 32 (FIGS. 3and 4), that are sharpened into conical points to engage the sway bracepipe 12. The conical tips 32 are generated prior to forming of the wireinto a U-shape. These tips 32 can be cold-worked or thermally treated togain additional hardness to improve the ability of the conical shape topenetrate into the sway brace pipe.

A pair of hooks 42 and 44 are coupled to the legs 22 and 24 to engagethe sway brace pipe 12. The hooks 42 and 44 may be stamped componentswith a U-shaped profile, each having a flattened central closed end orbody 46, and a pair C-shape hooked sides 48 and 50 extending from thecentral body 46. The sides 48 and 50 define respective openings or slots52 and 54 for receiving the sway brace pipe 12. The sides 48 and 50 arecoupled to the central body 46 at bottom edges 58 and 60 of the sides 48and 50. Otherwise the sides 48 and 50 may be freestanding, not coupledto any other part of the clamp 10.

The U-shape for the hooks 42 and 44 provides a symmetrical loadingcondition from the U-bolt 18 to the sway brace pipe 12. Each leg orhooked side 48 and 50 of each of the U-shaped stamped hooks 42 and 44has a V-shaped root 64 at one end of the each of the openings or slots52 and 54. The V-shaped root 64 is configured to accommodate severalsizes of the sway brace pipe 12, such as 1 inch (25.4 mm) diameter pipe12′ and a 1.25 inch (31.8 mm) diameter pipe 12″. The root 64 has acurved portion at the base of its “V” shape. Hook tips 66 along the topsof the openings 52 and 54 may be used to help retain the sway brace pipe12 in the openings 52 and 54. The open ends of the U-shaped stamping areleft open, but it should be recognized that optionally they can beconnect by the use of studs or rivets through pierced holes 68 (FIG. 4).

Swivel nuts are used to link the U-bolt 18 and the hooks 42 and 44together. The swivel allows for relative motion, and thereforeadjustment of the threaded connection. FIGS. 3 and 5 show one type ofswivel nut, a swivel nut 70 that has a flange 72 that bears against theflat, closed-end body 46 of the U-shaped hooks 42 and 44 when the swivelnut 70 is tightened on the threaded potions 26 and 28 of the U-bolt 18.Threads 76 of the swivel nut 70 may be left-handed to match those of theU-bolt 18. A center portion 80 of the length of the swivel nut 70 iscylindrical so as to freely turn within a hole 88 in the closed end 46of the U-shaped stamped hooks 42 and 44. The cylindrical center portion80 and the flange 72 contain the internal threads 76. At the end of thenut opposite the flange is a hex head potion 90 with an internaldiameter larger than the major diameter of the U-bolt threaded portions26 and 28. Between the hex portion 90 and the cylindrical portion 80 isa section of reduced diameter, a shear band 92. This reduced diametershear band 92 will break when a given torque is applied to the hexportion 90 of the nut 70. As alternative, the swivel nuts 70 may beproduced without the shear band.

FIGS. 4, 6A, and 6B show an alternative type of swivel nut, a swivelrivet-nut 94. The function of the swivel rivet-nut 94 is the same as theswivel nut 70 (FIG. 5), but with the added feature of self-retention inthe assembly. The swivel rivet nut 94 also contains a hex portion 96with oversized internal diameter 98 and a shear band 100. Alternatively,the shear band 100 may be excluded. The swivel rivet-nut 94 also has aflange 104 similar to the swivel nut 70; however it is installed on theoutside of the U-shaped hooks 42 and 44. Extending from the flange 104is a thin-wall tube rivet portion 108 of the component. The rivetportion 108 is a thin-wall tube that protrudes into the closed end 46 ofthe U-shaped hooks 42 and 44 through the hole 88. During factoryassembly, the tube 108 is swaged over, as shown at 112, to retain theswivel rivet-nut 94 into the U-shaped hooks 42 and 44.

When in the installed state, the sway brace pipe 12 is perpendicular andtangent to the service pipe 14, and the two components 12 and 14 are indirect contact. The main body 20 of the U-bolt 18 wraps around theservice pipe 14. The action of tightening the swivel nut 70 or swivelrivet-nut 94 creates a snug fit between the U-bolt 18 and the servicepipe 14. The action of the tightening the swivel nut 70 or swivelrivet-nut 94 causes the U-bolt tip 32 to protrude into the U-shapedhooks 42 and 44 and bear against the sway brace pipe 12. The tips 32 maydisplace and/or penetrate material of the sway brace pipe 12. Thisaction is directly opposed by the flange 72 of the swivel nut 70 or theflange 104 of the swivel rivet-nut 94 bearing against the flat, closedend 46 of the U-shaped stamped hooks 42 and 44. This action is alsosupported by the sway brace pipe 12 bearing against the V-shaped root 64of the open slots 52 and 54.

As shown in FIG. 3, one method of retention of the U-shaped hooks 42 and44 within the assembly is to capture the swivel nut 74 within theU-shaped hooks 42 and 44. In this embodiment two rectangular windows 120are pierced, one each in the legs or sides 48 and 50 of the U-shapedhooks 42 and 44, adjacent to the flat, closed end 46. The flange 72 ofthe swivel nut 70 protrudes slightly into each of the windows 120,creating a positive connection between the components. Another method,shown in FIG. 4, is to use an additional component 124 to restrain theU-shaped stamping (hooks) 42 and 44 to the U-bolt 18. The additionalcomponent 124 may be a washer, such as a suitable plastic washer orspring steel washer, for holding the hooks 42 and 44 in place. Thewasher acts as a spring clip that engages the threads of the U-bolt 18and expands against the inner surfaces of the hook ends 42 and 44. Thisprevents any movement of the hook ends (42 and 44) relative to thethreaded portions 26 and 28 of the U-bolt 18, along the axis of thethreaded portions 26 and 28.

One method of creating the “U” shaped component with a flat bottom isstamping. However, other possible manufacturing processes are casting,forging, or machining. A typical thickness is 0.25″ (6.4 mm). Typically,the width would be sufficiently larger than the sway brace pipe in orderto capture the sway brace pipe and carry the required load around it.This may be approximately 3″ (76 mm).

The stamped hook ends 42 and 44 may be stored loose on the U-bolt 18 androtated to be flat with the plane of the U-bolt for ease of shipping.During installation, the hooks 42 and 44 are rotated perpendicular tothe plane of the U-bolt 18 and slid into position on the swivel nuts.The open sides of the two hooks 42 and 44 can be oriented in the samedirection (as shown), or in opposite directions (not shown).

The sway brace assembly as installed resists any relative motion betweenthe service pipe and structure during a seismic event or other similarbuilding swaying event that might be seen in bomb blasts or other shockwaves impacting a building. The loads associated with the restraint ofthe service pipe to the structure are carried from the service pipe 14through the sway brace fitting or clamp 10, through the sway brace pipe12, through the structural attachment, and into the structure itself.The interlocking of the components of the sway brace fitting 10described above, with the service pipe 14 and the sway brace pipe 12,permits the brace fitting 10 to transmit these seismic loads.

One advantage of the brace fitting 10 is that all pipes, braced andbracing, can be in their final installed location prior to installationof the brace fitting. The brace fitting of clamp 10 will not disturb theposition of either of the pipes 12 and 14 during installation,minimizing the number and complexity of steps for installation. Priorsystems often require that the brace pipe be fed through the bracefitting to complete the installation.

Another advantage over prior systems is that with all pipes in theirfinal installed location, no disassembly of hardware is needed. Priorsystems often required that all parts be disassembled, the wire-formbody of the brace fitting be fed over the brace pipe and under/aroundthe service pipe, and all loose hardware be reassembled.

The brace fitting 10 provides positive, interlocking engagement betweenthe wire-form U-bolt 18 and the sway brace pipe 12, in addition to anyfrictional benefit gained by the clamping hooks. The positiveinterlocking engagement is derived from the sharpened ends or tips 32 ofthe U-bolt 18 that penetrate the sway brace pipe 12. Prior systems haveoften relied solely on friction for coupling.

Also prior sway brace fittings have sometimes been tensioned aroundservice pipes. The tension has been imparted by tightening against thesway brace pipe on either side of the service pipe. This action createsa bending moment in the sway brace pipe, causing it to bend around theservice pipe. The larger the service pipe being braced, the greater thisbending moment is, to the point that the clamp ceases to function.

The clamp or sway brace fitting 10 restricts any bending momentindependently attaching to the sway brace pipe on either side of theservice pipe being braced. The U-bolt 18 may be sized such that theassembly secures the service pipe 14 against the sway brace pipe 12without extreme bending.

The shear nut 70 and the shear rivet-nut 94 provides a means of limitingthe torque applied to the thread that imparts penetrating force on theU-bolt end into the sway brace pipe 12. Alternatively, torque may belimited by use of a torque wrench or visual indication to discourageovertightening a non-shear nut.

Some prior configurations allowed the sway brace fitting to quickly slipover a service pipe, but required that the brace pipe be fed through thesway brace fitting during assembly. In addition, some prior systemscould only accommodate one size of brace pipe (sway brace) per partnumber, requiring two models, one each for two sizes of brace pipe foreach one size of braced pipe.

The clamp 10 also expedites and simplifies installation, reducing thenumber of part configurations that need to be stocked for use. All ofthese are advantages of the clamp 10 (and the other sway brace fittingclamps described herein).

FIG. 7 shows an alternative clamp or sway brace fitting 10′ for clampingtogether a sway brace pipe 12 and a service pipe 14. Many of thefeatures of the clamp 10′ are the same as those of the clamp 10 (FIG.1). One difference is that a U-bolt 18′ of the clamp 10′ has bends 142and 144 in each of its legs 132 and 134. The bends 142 and 144 haveequal angles that maintain the parallelism of the ends of the threadedlegs 132 and 134. The additional offset created by the bends 142 and 144allows the hooked ends 152 and 154 to pass over the pipe 14 duringinstallation without interference.

The nuts 170 of the sway brace fitting 10′ are not shear nuts. The nuts170 are tightened without having their heads shear off. Otherwise thenuts 170 may be similar to the shear nut 70 (FIG. 5).

Turning now to FIGS. 8 and 9, a clamp or sway brace fitting 210 isshown. Features of the clamp 210 may be combinable with those of theclamp 10 (FIG. 1) described earlier, where suitable. The sway bracefitting clamp 210 is used to couple together a sway brace pipe 212 and apipe 214 to be secured, such as service pipe, for instance a sprinklerpipe. The clamp includes a U-bolt 218, to which a pair of hooks orhooked ends 222 and 224 are coupled. Nuts 226 and 228, which may beshear nuts, are used to cinch the hooks 222 and 224 against the swaybrace pipe 212.

A main body or curved central portion 230 is a U-shaped wire-form of theU-bolt 218, which wraps around a service pipe 214. Emanating fromopposite sides of the central portion 230 are straight threaded legs 232and 234 of the U-bolt 218. The threaded legs 232 and 234 extend awayfrom the sprinkler pipe 214, beyond the sway brace pipe 212, and throughthe hook ends 222 and 224, when the clamp 210 is in its installedposition. The threaded legs 232 and 234 have threaded portions 236 and238 that are threadedly engaged by the nuts 226 and 228. The nuts 226and 228 may be tightened to different locations along the threadedportions 236 and 238 to accommodate different diameters of sway bracepipe.

Each leg 232 and 234 of the U-bolt 218 has two bends 242 and 244 thatincrease the spacing between ends of the legs 232 and 234. The bends 242and 244 have equal angles that maintain the parallelism of the ends ofthe threaded legs 232 and 234. The offset created by the bends 242 and244 allows the hooked ends 222 and 224 to pass over the sprinkler pipe214 during installation without interference.

The hooked ends 222 and 224 are stamped components each with a U-shapedprofile, having respective rounded closed ends 252 and 254 fittingaround the threaded portions 236 and 238 of the U-bolt legs 232 and 234.The hooked end 222 has a pair of hooked sides or legs 256 and 258, andthe hooked end 224 has a pair of hooked sides or legs 262 and 264. Withreference now in addition to FIG. 10, each of the legs 256, 258, 262,264 of the U-shaped stamping has a V-shaped root 270 that defines anopen slot 272 for receiving the sway brace pipe 212 within. The includedangle of the V-shape root 270 defining the open slot 272 is 60°,although it should be recognized that any acute angle from 0 to 90°would function similarly. The V-shape root 270 has a radiused portion atits base. The open cutout with the V-shaped root 270 is designed toaccommodate multiple sizes of sway brace pipe 212, for instanceincluding 1 inch (25.4 mm) diameter pipe 212′ and a 1.25 inch (31.8 mm)diameter pipe 212″, to give only one example among many possibilities.

The edge profile of the open slot 272 and the V-shaped root 270 containsteeth 276 to engage the brace pipe 212. The teeth 276 each have anincluded angle of generally 90°, although it should be recognized thatthe angle could be greater or lesser. The teeth 276 are orientedgenerally so that their centerline is directed inward toward center ofthe brace pipe 212.

The application of the nuts 226 and 228 to the hooked ends 222 and 224,resisted by the sway brace pipe 212, imparts a moment to the hooked ends222 and 224. To provide a second point of resistance against thismoment, rivets 282 and 284 are added, through holes 286 and 288 in thehooked ends 222 and 224. The rivets 282 and 284 bear against thethreaded portions 236 and 238 of the U-bolt 218. It should be recognizedthat the open ends of the U-shaped stamping (hooked ends) 222 and 224can be free, or may be connected to one another by the use of stud(s) orrivet(s) 292 and 294 through pierced hole(s) 296 and 298.

The clamping pressure to ensure the function of the brace fitting isgenerated through the use of a pair of nuts 226 and 228, one on eachthreaded portion 236 and 238 of the U-bolt 218. The nuts 226 and 228 maybe tightened along the threaded portions 236 and 238 to press downagainst top edges of the hooked ends 222 and 224, through interveningwashers 300 and 301. Referring now to FIGS. 11 and 12, the nuts 226 and228 may be substantially identical, and may each include three sections302, 304, and 306 along an axis 310 of the fastener 226, 228. The firstportion or section 302 has a smooth outside surface 312, and internalthreads 314. The central portion or section 304 is a shear band having areduced diameter of the external surface of the fastener. The reduceddiameter may be in the form of a groove 318. The inside diameter of thisportion or section 304 is smooth. The combination of the external grooveand smooth internal diameter produce a substantially thinnercross-section than the other two portions 302 and 306 of the fastener orshear nut. Alternatively the shear band may be excluded, leaving thenuts 226 and 228 as non-shear nuts. The third section 306 of thefastener is a portion allowing for application of torque to the threads.The external surface of the section 306 has a cross-section typically inthe form of a hexagon. However, it should be recognized that othershapes would produce an equivalent result. The internal surface of thethird portion 306 is a smooth diameter (cylindrical surface) 324 thatcan be of equal or greater diameter than the internal diameter of thesecond portion 304.

Upon the application of sufficient torque to the third portion 306 ofthe shear nut fasteners 226 and 228, the shear band 318 will fracture,preventing the application of any additional torque to the threadedportion of the fasteners 226 and 228. By their nature the threadedfasteners limit the torque applied to the thread, limiting the clampingforce exerted by the nut onto the u-bolt.

Installed on the sprinkler pipe 214 and the brace pipe 212, the bracefitting 210 surrounds the two pipes 212 and 214. The hooks 222 and 224engage the outermost surface of the brace pipe 212. The U-bolt 218surrounds (fits around) the outermost surface of the sprinkler pipe 214.The installation of the brace fitting 210 compresses the brace pipe 212and the sprinkler pipe 214 together, eliminating movement between thesprinkler pipe 212 and brace pipe 214 during a seismic event. The shearnuts 226 and 228 may be tightened to compress the pipes 212 and 214together. The brace fitting clamp 210 advantageously may be installedwith both of the pipes 212 and 214 already in place.

The components of the brace fitting clamps 10 and 210 may be made of anyof a variety of suitable materials, for example steel or iron. Onemethod of creating the hooked end components 222 and 224 is stamping.However, other manufacturing processes are casting, forging, ormachining. A typical thickness is 0.125 inch (3.2 mm). Typically, thewidth (height) would be sufficiently larger than the sway brace pipe 212in order to capture the sway brace pipe 212 and carry the required loadaround it. This may be about 2.5 inches (64 mm). However, it will beappreciated that a wide range of other dimensions are possible.

The sway brace assembly as installed resists any relative motion betweenthe service pipe and structure during a seismic event. The loadsassociated with the restraint of the service pipe to the structure arecarried from the sprinkler system pipe through the sway brace fitting,through the sway brace pipe, through the structural attachment, and intothe structure itself. The interaction of the components of the swaybrace fitting, described above, with the service pipe, and the swaybrace pipe permits the brace fitting to transmit these seismic loads.

The sway brace fitting clamp 210 advantageously expedites and simplifiesinstallation, reducing the number of part configurations, and creatingfunctional parts for small diameter sprinkler system and other pipes andsystems needing bracing.

Turning now to FIGS. 13 and 14, a sway brace fitting clamp 410 is usedfor coupling together a sway brace pipe 412 and a service pipe or otherobject to be braced 414. The clamp 410 includes a body 416 that engagesthe pipe 414, and a pair of hooks 422 and 424 that engage the sway bracepipe 412, with a threaded engagement 428 that is used to tighten thecoupling of the clamp 410 together. The threaded connection orengagement 428 is used secure the engagement of the body 416 against theobject 414, and the engagement of the hooks 422 and 424 against the swaybrace 412. It will be appreciated that all of the embodiments describedherein involve use of hooks to engage a sway brace pipe (or otherobject), use of a body to engage a service pipe, and a threadedengagement to secure the clamp in place against the sway brace pipe andthe service pipe. However the configuration of the embodiment shown inFIGS. 13 and 14 differs in some regards from that shown in the otherembodiments described herein.

The body 416 includes a center section 432 with a pair of straightextensions 434 and 436 extending outward from sides of the centersection 432. The center section 432 is curved, wrapping around part ofthe service pipe object 414 with its inner surface engaging the outersurface of the service pipe or other object 414. The center section 432has a slot 440 therein, which allows for better gripping of the servicepipe or other object 414.

The extensions 434 and 436 have holes 444 and 446 in them. Bolts 448 and450 are inserted in the holes, with washers 454 and 456 between the boltheads 448 and 450, and the extensions 434 and 436. The bolts 448 and 450are used to secure the body 416 to the hooks 422 and 424. The hooks 422and 424 may have many features in common with the hooks 42 and 44(FIG. 1) described above. To name a few of the common features, thehooks 422 and 424 may be U-shape stamped pieces of sheet metal, withopenings or slots having a V-shape root that is configured toaccommodate several sizes of sway brace pipe. The V-shape root is a pairof converging straight surfaces that aids in accommodating differentsway brace pipe sizes.

The threaded shafts of the bolts 448 and 450 are threaded into nuts 462and 464 that are secured to or within the bottom surfaces 472 and 474 ofthe hooks 422 and 424. The nuts 462 and 464 may be attached to the hooks422 and 424, or may be otherwise be secured within the hooks 422 and 424such that the nuts 462 and 464 are restrained from rotation. Theattachment/securing of the nuts 462 and 464 to the hooks 422 and 424 maybe by any of a variety of suitable attachment methods, such as welding,staking, or capturing.

The bolts 448 and 450 and the nuts 462 and 464 together make up thethreaded engagement 428 that secures together the pipes (or bars orother objects) 412 and 414. It will be appreciated that the threadedengagement shown in FIGS. 13 and 14 has a different configuration anddifferent elements/features than the threaded engagements shown in otherillustrated embodiments described above and elsewhere herein.

The shafts of the bolts 448 and 450 may have bolt tips 478 and 480 withconical sharp ends. The bolt tips 478 and 480 may be used to engage thesway brace pipe or bar 412. The tightening the threaded engagement 428(tightening of the bolts 448 and 450) may cause the hooks 422 and 424 tobe drawn toward the body 416, perhaps also drawing the sway brace bar orpipe 412 toward the service pipe or other object 414. The bolts 448 and450 may eventually be screwed in far enough so that the bolt tips 478and 480 make contact with the outer surface of the sway brace pipe orbar 412. The bolt tips 478 and 480 may displace some material of thepipe or bar 412, making indentations that are engaged by the bolt tips478 and 480. This may provide an additional engagement that helps holdthe clamp 410 against the objects 412 and 414. Toward this end, the bolttips 478 and 480 may terminate at or above a plane of tangency 490 whenthe bolts 448 and 450 are fully installed onto the hooks 422 and 424.

The hooks 422 and 424 may each be made from a single piece of sheetmetal, such as suitable steel. Studs or rivets 492 and 494 may be usedto hold together the open ends of the C-shaped sides 496 and 498 of thehooks 422 and 424.

FIGS. 15 and 16 show another embodiment, a sway brace fitting clamp 510that is used to couple together a sway brace 512 (such as a sway bracepipe or bar) and an object 514 (such as a service pipe). Many of thefeatures of the clamp 510 are similar to those of the clamp 410 (FIGS.13 and 14), such as the use of a body 516 to engage the object 514, apair of hooks 522 and 524 to engage the sway brace 512, and a threadedengagement or connection 528 to secure the clamp 510 to the sway brace512 and the object 514. Further details of the similar features areomitted, but it will be appreciated that such details may be found inthe descriptions of other embodiments, such as in the details of thebody 416 (FIGS. 13 and 14) and the hooks 422 and 424 (FIGS. 13 and 14).

One difference in the clamp 510 is that the body 516 has a pair ofthreaded studs 530 and 532 fixedly attached to extensions 534 and 536 ofthe body 516. The studs 530 and 532 may be staked, welded, or otherwiseattached to the extensions 534 and 536. The threaded studs 530 and 532pass through holes in the hooks 522 and 524, and are secured by nuts 540and 542 threaded onto the studs 530 and 532. The studs 530 and 532 andthe nuts 540 and 542 constitute the threaded engagement 528. The studs530 and 532 may have conical tips 550 and 552, that may be used toengage the sway brace 512 in a manner similar to the engagement of thebolt tips 478 and 480 (FIG. 13) with the sway brace 412 (FIG. 13).

FIGS. 17 and 18 show a further embodiment, a clamp 610. The clamp 610includes many of the features of various embodiments described above.The clamp 610 includes hooks 622 and 624 that engage a sway brace 612,and a body 616 that engages an object 614 such as a service pipe. Thehooks 622 and 624 may have features similar to those of the hooks 222and 224 (FIGS. 8 and 9), with perhaps toothed inner surfaces to betterengage the sway brace 612. The body 616 may have studs 630 and 632fixedly attached to extensions 634 and 636, in a manner similar to thatof the body 516 (FIGS. 15 and 16). For example, the studs 630, and 632may be staked, welded, or threadedly attached, such as by use ofsuitable hex bolts as the studs 630 and 632, threaded into holes in theextensions (or held in place using washers). The studs 630 and 632 mayhave threaded portions 637 and 638 that are similar to the threadedportions 236 and 238 (FIG. 9) in that the threaded portions 637 and 638that extend above the sway brace 612, and pass through the hooks 622 and624. The threaded portions 637 and 638 may be threadedly engaged by nuts646 and 648 that may have features similar to the nuts 226 and 228(FIGS. 8 and 9).

FIG. 19 shows still another embodiment, a clamp 710 that has a body 716that is formed as a single part with a pair of hooks 722 and 724 thatengage and clamp onto a sway brace 712. The sway-brace-receivingopenings 742 and 744 in the hooks 722 and 724 may be similar to theopenings in other embodiments described herein, for example having aV-shaped root configured to accommodate several sizes of sway brace (orrestraint), and having a curved portion at the base of the “V” shape.The hooks 722 and 724 have hook tips 752 and 754 along the tops of theopenings, to help retain the sway brace 712 within the openings 742 and744.

A threaded engagement 728 aids in keeping the clamp 710 secured to thesway brace 712 and to an object 714, such as a service pipe. Thethreaded engagement 728 includes a curved saddle 760 that is heldagainst the object 714 by a set screw (or bolt) 762. The set screw orbolt 762 is threaded into a thread form hole 764 at the bottom of thebody 716. Tightening the set screw or bolt 762 will push the saddle 760against the object 714, and/or pull the hooks 722 and 724 down towardthe saddle 760, more firmly into engagement with the sway brace 712. Itwill be appreciated that a variety of other threaded engagementconfigurations are possible as alternatives. For example, one or moreadditional items, such as lock washers, may be used to hold the setscrew or bolt 762.

Although the invention(s) has (have) been shown and described withrespect to a certain preferred embodiment or embodiments, it is obviousthat equivalent alterations and modifications will occur to othersskilled in the art upon the reading and understanding of thisspecification and the annexed drawings. In particular regard to thevarious functions performed by the above described elements (components,assemblies, devices, compositions, etc.), the terms (including areference to a “means”) used to describe such elements are intended tocorrespond, unless otherwise indicated, to any element which performsthe specified function of the described element (i.e., that isfunctionally equivalent), even though not structurally equivalent to thedisclosed structure which performs the function in the hereinillustrated exemplary embodiment or embodiments of the invention. Inaddition, while a particular feature of the invention may have beendescribed above with respect to only one or more of several illustratedembodiments, such feature may be combined with one or more otherfeatures of the other embodiments, as may be desired and advantageousfor any given or particular application.

1. A sway brace fitting clamp for coupling a sway brace to an object,the clamp comprising: a curved body that wraps at least in part aroundthe object; a pair of hooks coupled to respective ends of the body,wherein the hooks engage the sway brace on opposite sides of the object,and wherein the hooks have openings for receiving the sway brace; and athreaded engagement that may be tightened to clamp the sway brace andthe object together; whereby, in an installed position, the curved bodyand the hooks are positioned by adjusting the threaded engagement, tosecure the clamp; and wherein the hooks each include a pair of sideplates, with the pair of side plates held together by one or more studsor rivets.
 2. A sway brace fitting clamp for coupling a sway brace to anobject, the clamp comprising: a curved body that wraps at least in partaround the object; a pair of hooks coupled to respective ends of thebody, wherein the hooks engage the sway brace on opposite sides of theobject, wherein the hooks have openings for receiving the sway brace,and wherein the hooks have free distal ends with respect to the ends ofthe body; and a threaded engagement that may be tightened to clamp thesway brace and the object together; wherein each of the hooks provides adistributed contact with the sway brace along a curved line of the hook,with the contact over multiple points or an area of the hook; whereby,in an installed position, the curved body and the hooks are positionedby adjusting the threaded engagement, to secure the clamp.
 3. The clampof claim 2, wherein the threaded connection includes: threaded ends thatare coupled to the body; and nuts threaded onto the threaded ends. 4.The clamp of claim 3, wherein the threaded ends have sharp tips forpressing against the sway brace when the sway brace is within theopenings defined by the hooks.
 5. The clamp of claim 2, wherein thehooks have a U shape, with each of the hooks having a central body and apair of sides; and wherein the sides of each of the hooks defines anopening therein for receiving the sway brace pipe.
 6. The clamp of claim5, wherein the threaded ends pass through holes in the central bodies ofthe hooks.
 7. The clamp of claim 5, wherein the central bodies of thehooks wrap around the threaded ends.
 8. The clamp of claim 5, whereinfor each of the hooks the sides are diametrically opposed on oppositesides of one of the threaded ends.
 9. The clamp of claim 2, wherein theopenings of the hooks each have a V-shape root for receiving the swaybrace.
 10. The clamp of claim 2, wherein the hooks have teeth facinginward toward the openings.
 11. The clamp of claim 2, wherein the bodyis part of a U-shape bolt.
 12. The clamp of claim 2, wherein the bodyhas a curved center section, and a pair of extensions extending outwardfrom ends of the curved center section.
 13. The clamp of claim 12,wherein threaded studs are fixedly attached to the extensions.
 14. Theclamp of claim 13, wherein the threaded studs are threadedly engaged bynuts, as part of the threaded engagement.
 15. The clamp of claim 14,wherein the nuts are located within the hooks.
 16. The clamp of claim12, further comprising: bolts that pass through holes in the extensions;and nuts that engage the bolts as part of the threaded engagement. 17.The clamp of claim 2, wherein the threaded engagement includes: a curvedsaddle that engages the object; and a threaded member that is threadedlyengaged with a hole in the body, and presses the saddle into engagementwith the object.
 18. The clamp of claim 2, in combination with the swaybrace.
 19. The combination of claim 18, further in combination with theobject, wherein the object is a service pipe.
 20. The combination ofclaim 18, wherein the sway brace is a round sway brace.
 21. Thecombination of claim 20, wherein the round sway brace is a sway bracepipe.
 22. The combination of claim 20, wherein the round sway brace is asway brace bar.
 23. The sway brace fitting of claim 2, wherein the freedistal ends of each of the hooks includes a pair of side plates.
 24. Amethod of seismic bracing, the method comprising: placing a sway bracesubstantially perpendicular to a service pipe; after the placing,engaging the sway brace and the service pipe with a sway brace fittingclamp, with the hooks engaging the sway brace on opposite sides of theservice pipe, wherein the engaging does not require movement of eitherthe sway brace or the service pipe; and tightening the sway bracefitting clamp to couple together the sway brace and the service pipe;wherein the engaging includes: placing a pair of hooks of the clamparound the sway brace; and placing a body of the clamp at least in partaround the service pipe, with each of the hooks providing a distributedcontact with the sway brace along a curved line of the hook, with thecontact over multiple points or an area of the hook; wherein the hooksare mechanically coupled to the body before and during the placing thebody and the placing the hooks.
 25. The method of claim 24, wherein thetightening causes sharp tips of the clamp to engage the sway brace. 26.The method of claim 24, wherein the tightening causes a saddle of theclamp to press against the service pipe.
 27. The method of claim 24,wherein the tightening includes: contacting the service pipe with thebody; and contacting the sway brace with the hooks.